Flexible snapshot in endpoint detection
US6821794B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2002 |
| Grant date | Nov 23, 2004 |
| Priority date | — |
| Expiry date | Jan 31, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A system and method for determining endpoint detection in semiconductor wafer planarization is provided. The system and method provide a flexible solution that can compensate for baseline variability induced errors that may otherwise occur in endpoint detection. The system uses an endpoint detection signal that monitors the optical characteristics of the wafer being planarized. The system and method continue to monitor the detection signal during planarization until it meets endpoint criterion that indicates endpoint completion. When the endpoint criterion is reached, a new snapshot is taken from a previous time period and a new baseline is calculated. The endpoint detection signal is then recalculated based upon the new baseline and the recalculated detection signal is again compared to the endpoint criterion. If the recalculated endpoint detection signal again substantially meets the endpoint criterion then the detection of endpoint is confirmed. If the recalculated detection signal no longer meets the endpoint criterion, the planarization process continues with the new baseline used as the basis for endpoint detection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.